Ive been in a Japanese mood lately, and watched some videos on the sword smithing process. The polishing part takes up to two weeks to complete. Beyond looks it stated that it makes the cut cleaner. Sorta like a hairless swimmer. Sorry for the gross anology.

Heres how this relates to razors in my mind. At the 1k level we establish a bevel, at the 4k level we "hone" and sharpen the blade, and at the 8k level we polish. But we keep going much farther than just 8k in most cases. Why? My thoughts are that because a razor is a shearing action you want to remove as much resistenace from the cut as possible. Low drag means that the hair isnt getting pulled, and then more comfortable. This might have been covered, but this is just my thoughts.